A first tool shape measurement device in the related art acquires a contour of a tool tip end portion by moving an optical non-contact sensor relative to a tool spindle. The first tool shape measurement device selects a correction table corresponding to the contour shape from a plurality of correction tables which are beforehand determined for the respective contour shapes of the tip end portion of the tool. In addition, the first tool shape measurement device obtains a correction amount of the tool dimensions on the basis of the correction table and obtains actual tool dimensions (the length and diameter of the tool) using the correction amount (for example, refer to Patent Literature 1).
In addition, a second tool shape measurement device in the related art includes a tool holding mechanism capable of rotating a tool about the center axis. The second tool shape measurement device fits a tool shape imaged while rotating the tool to a cylinder. In addition, the second tool shape measurement device determines a tool model on the basis of the result of pattern matching between the dimensions of the cylinder, the taken image, and tool models, and generates tool dimensional data using the tool model (for example, refer to Patent Literature 2).